This invention generally relates to a drive mechanism for actuating a pair of pivotally mounted jaws and is particularly adapted for use with those automatic handling devices known as pick-and-place units.
Devices of this general type are known and include that disclosed in U.S. Pat. No. 3,386,297 issued June 4, 1978. In the mechanism disclosed therein, a pair of levers or jaws are pivotally attached to a housing and driven between open and closed positions thereof by means of a reciprocal center drive member mounted in the housing and positioned between the levers. Line contact is provided between the drive member and the levers by means of the coaction of a disc 58 with knife edge portions 60 and 62. In addition stop means in the form of a threaded pin mounted in each of the jaws and engageable with the housing are included so as to selectively limit the extent of pivotal movement between the levers. The citation and discussion of the above patent constitutes applicant's Prior Art Statement. Although operable for the intended purposes, such above referred structure is overly complex and accordingly is expensive to produce. In addition, lower jaw portions of many presently utilized pick-and-place units are adapted for mounting of jaw extensions thereon and when so utilized such extensions may interfere with the adjustment of the stop means and accordingly necessitate their removal in order to accomplish adjustment of the jaws.
It is accordingly an object of the present invention to provide a more direct and less complex drive mechanism adapted for use in pick-and-place units as above described and which is less costly to produce than presently available commercial units.
A still further object of the present invention is the provision of a drive mechanism of the above indicated nature including stop means capable of trouble-free operation and which can additionally be adjusted in situ without the necessity of removing component parts of such pick-and-place units.
These and other objects of the present invention are accomplished by a device for driving a pair of jaws which are in turn pivotally supported from a housing towards and away from each other. Such jaws include inner respectively opposed surfaces each having an arcuate recess formed therein so as to cooperatively form a drive socket in which a generally cylindrical bushing is laterally disposed and in slidable face-to-face contact therewith. The terminal segments of a bifurcated drive member serve to laterally support the bushing. When the drive member is vertically reciprocated, it forces the jaws to pivotally move towards and away from each other in the intended manner. A threadably adjusted pin is mounted within a threaded, laterally extending bore provided in one of the jaws at the upper head portion thereof such that the pin may extend in between opposed upper face surfaces of the jaws and thus limit their movement towards and away from each other.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawing.